Forestry

Forestry is the hardest side-load service a hydraulic cylinder sees short of demolition. A grapple never grabs a log dead-center; it clamps an irregular, shifting load that puts bending and torsion into the rod on nearly every cycle. A splitter drives full tonnage into knotty, uneven wood and stalls against it. The cylinders that survive are the ones designed around off-axis loading and impact from the start, not the ones that happen to have enough bore.

The engineering answer is in the bearings and the stop tubes. Long rod bearings and correctly proportioned stop tubes carry the bending moment that comes standard on a grapple or a loader arm, keeping the rod from cocking in the gland and galling one side of the bore. On splitters and processors, the priority shifts to fast cycle time and the ability to stall repeatedly against a hard load without cooking the seals — polyurethane packages handle that heat and shock far better than standard Buna.

This is also a world of dents, bark, and sap, so the rod finish and wiper have to shrug off abrasion, and the tube and caps have to take a hit without going out of round. We build grapple, splitter, and loader cylinders to the print, size the bearings and stop tubes for the real geometry of the boom, and reverse-engineer obsolete units from the worn part when a machine has outlived its parts supply. Every cylinder is pressure-tested before it ships, because a grapple that lets go of a suspended log is not a warranty conversation.

Representative applications

• Grapple clamp and rotate cylinders
• Log splitter and processor cylinders
• Knuckleboom loader lift and slew cylinders
• Feller-buncher accumulator and tilt cylinders
• Delimber and slasher actuation